Davidson Defense Longbow 10.5-inch Carbine-Gas 5.56 NATO AR-15 Drop-In Quad-Rail Handguard Pistol Upper Build Kit

Longbow 10.5-inch 5.56 NATO AR-15 Upper Build Kit

The Longbow is built around a 10.5-inch front sight base barrel chambered in 5.56 NATO, paired with a 7075-T6 aluminum upper receiver. It pairs a 7-inch M4 carbine-length drop-in quad-rail handguard, finished in black, with a tanker-style three-port muzzle brake at the muzzle. BCG and charging handle are not included, leaving the buyer to supply those components separately.

Key Features

• 10.5-inch 5.56 NATO barrel with front sight base configuration
• Carbine-length gas system with stainless steel gas tube
• 7075-T6 aluminum upper receiver with M4 feed ramps
• 7-inch M4 carbine-length drop-in quad-rail handguard, four-sided Picatinny rail
• A2-style front sight base, USA-made steel components
• Tanker-style three-port muzzle brake, black
• BCG and charging handle are not included.

Barrel and Gas System

The barrel runs 10.5 inches long, chambered in 5.56 NATO and built in a front sight base configuration rather than a low-profile gas block setup. Gas cycles back to the action through a carbine-length system, running a carbine-length stainless steel gas tube. This barrel length paired with a carbine-length gas system gives the build a shorter dwell time than a typical mid-length or rifle-length setup.

Front Sight Base and Upper Receiver

Mounted on the barrel is an A2-style front sight base, fitted with USA-made steel components including the front sight post, plunger, and spring. The upper receiver is machined from 7075-T6 aluminum with an anodized finish, cut with M4 feed ramps for smooth feeding and fitted with a standard AR-15 forward assist assembly. The ejection port carries a standard .223/5.56 door with its rod and spring installed.

Handguard

The handguard is a 7-inch M4 carbine-length drop-in design finished in black, built around a four-sided Picatinny quad rail rather than a slimmer M-LOK profile. It mounts using a Colt AR-15 delta ring assembly along the barrel.

Muzzle Device

Capping the muzzle is a tanker-style three-port muzzle brake finished in black, with a 0.3-inch bore diameter sized for 5.56 NATO. It threads onto the barrel's 1/2x28 pattern and is secured with the included 1/2-inch black crush washer.

Follow all manufacturer instructions and safe handling practices.

Ensure compliance with all applicable federal, state, and local laws.

BCG and charging handle are not included.